Investment Securities (Details 8) (USD $) In Millions, unless otherwise specified	Jun. 30, 2011	Dec. 31, 2010
Investment securities
Available-for-sale securities, total, amortized cost	$ 51,870	$ 51,855
Held-to-maturity securities, total, amortized cost	13,280	1,469
Available-for-sale securities, total, fair value	52,299
Held-to-maturity securities, total, fair value	13,431	1,419
Available-for-sale securities, total, weighted average maturity in years	7.4
Held-to-maturity securities, total, weighted average maturity in years	5.2
Available-for-sale securities, total, weighted average yield	3.33%
Held-to-maturity securities, total, weighted average yield	2.26%
Total investment securities amortized cost	65,150	53,324
Total investment securities, percentage	100.00%	100.00%
Mortgage Backed Securities [Member]
Investment securities
Available-for-sale securities, maturing in one year or less, amortized cost	227
Available-for-sale securities, maturing after one year through five years, amortized cost	15,070
Available-for-sale securities, maturing after five years through ten years, amortized cost	18,589
Available-for-sale securities, maturing after ten years, amortized cost	6,626
Available-for-sale securities, total, amortized cost	40,512
Held-to-maturity securities, maturing in one year, amortized cost	9
Held-to-maturity securities, maturing after one year through five years, amortized cost	6,450
Held-to-maturity securities, maturing after five years through ten years, amortized cost	3,477
Held-to-maturity securities, maturing after ten years, amortized cost	706
Held-to-maturity securities, total, amortized cost	10,642
Available-for-sale securities, maturing in one year or less, fair value	226
Available-for-sale securities, maturing after one year through five years, fair value	15,361
Available-for-sale securities, maturing after five years through ten years, fair value	18,843
Available-for-sale securities, maturing after ten years, fair value	6,641
Available-for-sale securities, total, fair value	41,071
Held-to-maturity securities, maturing in one year, fair value	6
Held-to-maturity securities, maturing after one year through five years, fair value	6,577
Held-to-maturity securities, maturing after five years through ten years, fair value	3,499
Held-to-maturity securities, maturing after ten years, fair value	715
Held-to-maturity securities, total, fair value	10,797
Available-for-sale securities, maturing in one year or less, weighted average maturity in years	0.7
Available-for-sale securities, maturing after one year through five years, weighted average maturity in years	3.7
Available-for-sale securities, maturing after five years through ten years, weighted average maturity in years	6.5
Available-for-sale securities, maturing after ten years, weighted average maturity in years	13.3
Available-for-sale securities, total, weighted average maturity in years	6.6
Held-to-maturity securities, maturing in one year of less, weighted average maturity in years	0.8
Held-to-maturity securities, maturing after one year through five years, weighted average maturity in years	4.2
Held-to-maturity securities, maturing after five years through ten years, weighted average maturity in years	6.7
Held-to-maturity securities, maturing after ten years, weighted average maturity in years	14.1
Held-to-maturity securities, total, weighted average maturity in years	5.7
Available-for-sale securities, maturing in one year of less, weighted average yield	4.07%
Available-for-sale securities, maturing after one year through five years, weighted average yield	3.37%
Available-for-sale securities, maturing after five years through ten years, weighted average yield	2.71%
Available-for-sale securities, maturing after ten years, weighted average yield	1.51%
Available-for-sale securities, total, weighted average yield	2.77%
Held-to-maturity securities, maturing in one year of less, weighted average yield	1.02%
Held-to-maturity securities, maturing after one year through five years, weighted average yield	3.07%
Held-to-maturity securities, maturing after five years through ten years, weighted average yield	1.84%
Held-to-maturity securities, maturing after ten years, weighted average yield	1.39%
Held-to-maturity securities, total, weighted average yield	2.55%
Total investment securities amortized cost	51,154	40,654
Total investment securities, percentage	78.50%	76.20%
U.S. Treasury and agency [Member]
Investment securities
Available-for-sale securities, maturing in one year or less, amortized cost	819
Available-for-sale securities, maturing after one year through five years, amortized cost	986
Available-for-sale securities, maturing after five years through ten years, amortized cost	47
Available-for-sale securities, maturing after ten years, amortized cost	18
Available-for-sale securities, total, amortized cost	1,870
Held-to-maturity securities, maturing in one year, amortized cost	0
Held-to-maturity securities, maturing after one year through five years, amortized cost	2,301
Held-to-maturity securities, maturing after five years through ten years, amortized cost	0
Held-to-maturity securities, maturing after ten years, amortized cost	62
Held-to-maturity securities, total, amortized cost	2,363	165
Available-for-sale securities, maturing in one year or less, fair value	819
Available-for-sale securities, maturing after one year through five years, fair value	987
Available-for-sale securities, maturing after five years through ten years, fair value	49
Available-for-sale securities, maturing after ten years, fair value	18
Available-for-sale securities, total, fair value	1,873
Held-to-maturity securities, maturing in one year, fair value	0
Held-to-maturity securities, maturing after one year through five years, fair value	2,322
Held-to-maturity securities, maturing after five years through ten years, fair value	0
Held-to-maturity securities, maturing after ten years, fair value	62
Held-to-maturity securities, total, fair value	2,384
Available-for-sale securities, maturing in one year or less, weighted average maturity in years	0.3
Available-for-sale securities, maturing after one year through five years, weighted average maturity in years	1.9
Available-for-sale securities, maturing after five years through ten years, weighted average maturity in years	7.4
Available-for-sale securities, maturing after ten years, weighted average maturity in years	11.7
Available-for-sale securities, total, weighted average maturity in years	1.5
Held-to-maturity securities, maturing in one year of less, weighted average maturity in years	0
Held-to-maturity securities, maturing after one year through five years, weighted average maturity in years	2.6
Held-to-maturity securities, maturing after five years through ten years, weighted average maturity in years	0
Held-to-maturity securities, maturing after ten years, weighted average maturity in years	10.8
Held-to-maturity securities, total, weighted average maturity in years	2.8
Available-for-sale securities, maturing in one year of less, weighted average yield	1.71%
Available-for-sale securities, maturing after one year through five years, weighted average yield	1.14%
Available-for-sale securities, maturing after five years through ten years, weighted average yield	4.49%
Available-for-sale securities, maturing after ten years, weighted average yield	3.66%
Available-for-sale securities, total, weighted average yield	1.50%
Held-to-maturity securities, maturing in one year of less, weighted average yield	0.00%
Held-to-maturity securities, maturing after one year through five years, weighted average yield	1.01%
Held-to-maturity securities, maturing after five years through ten years, weighted average yield	0.00%
Held-to-maturity securities, maturing after ten years, weighted average yield	3.22%
Held-to-maturity securities, total, weighted average yield	1.06%
Total investment securities amortized cost	4,233	2,724
Total investment securities, percentage	6.50%	5.10%
Obligations of state and political subdivisions [Member]
Investment securities
Available-for-sale securities, maturing in one year or less, amortized cost	14
Available-for-sale securities, maturing after one year through five years, amortized cost	2,312
Available-for-sale securities, maturing after five years through ten years, amortized cost	2,424
Available-for-sale securities, maturing after ten years, amortized cost	2,059
Available-for-sale securities, total, amortized cost	6,809
Held-to-maturity securities, maturing in one year, amortized cost	0
Held-to-maturity securities, maturing after one year through five years, amortized cost	6
Held-to-maturity securities, maturing after five years through ten years, amortized cost	3
Held-to-maturity securities, maturing after ten years, amortized cost	15
Held-to-maturity securities, total, amortized cost	24	27
Available-for-sale securities, maturing in one year or less, fair value	14
Available-for-sale securities, maturing after one year through five years, fair value	2,321
Available-for-sale securities, maturing after five years through ten years, fair value	2,420
Available-for-sale securities, maturing after ten years, fair value	1,927
Available-for-sale securities, total, fair value	6,682
Held-to-maturity securities, maturing in one year, fair value	0
Held-to-maturity securities, maturing after one year through five years, fair value	6
Held-to-maturity securities, maturing after five years through ten years, fair value	4
Held-to-maturity securities, maturing after ten years, fair value	14
Held-to-maturity securities, total, fair value	24
Available-for-sale securities, maturing in one year or less, weighted average maturity in years	0.6
Available-for-sale securities, maturing after one year through five years, weighted average maturity in years	4.0
Available-for-sale securities, maturing after five years through ten years, weighted average maturity in years	5.9
Available-for-sale securities, maturing after ten years, weighted average maturity in years	21.1
Available-for-sale securities, total, weighted average maturity in years	9.8
Held-to-maturity securities, maturing in one year of less, weighted average maturity in years	0.2
Held-to-maturity securities, maturing after one year through five years, weighted average maturity in years	3.5
Held-to-maturity securities, maturing after five years through ten years, weighted average maturity in years	6.2
Held-to-maturity securities, maturing after ten years, weighted average maturity in years	15.6
Held-to-maturity securities, total, weighted average maturity in years	11.2
Available-for-sale securities, maturing in one year of less, weighted average yield	6.10%
Available-for-sale securities, maturing after one year through five years, weighted average yield	6.50%
Available-for-sale securities, maturing after five years through ten years, weighted average yield	6.76%
Available-for-sale securities, maturing after ten years, weighted average yield	6.92%
Available-for-sale securities, total, weighted average yield	6.72%
Held-to-maturity securities, maturing in one year of less, weighted average yield	7.06%
Held-to-maturity securities, maturing after one year through five years, weighted average yield	8.27%
Held-to-maturity securities, maturing after five years through ten years, weighted average yield	5.36%
Held-to-maturity securities, maturing after ten years, weighted average yield	5.50%
Held-to-maturity securities, total, weighted average yield	6.15%
Total investment securities amortized cost	6,833	6,862
Total investment securities, percentage	10.50%	12.90%
Asset backed Securities [Member]
Investment securities
Available-for-sale securities, maturing in one year or less, amortized cost	2
Available-for-sale securities, maturing after one year through five years, amortized cost	151
Available-for-sale securities, maturing after five years through ten years, amortized cost	644
Available-for-sale securities, maturing after ten years, amortized cost	96
Available-for-sale securities, total, amortized cost	893
Held-to-maturity securities, maturing in one year, amortized cost	3
Held-to-maturity securities, maturing after one year through five years, amortized cost	71
Held-to-maturity securities, maturing after five years through ten years, amortized cost	18
Held-to-maturity securities, maturing after ten years, amortized cost	27
Held-to-maturity securities, total, amortized cost	119
Available-for-sale securities, maturing in one year or less, fair value	12
Available-for-sale securities, maturing after one year through five years, fair value	156
Available-for-sale securities, maturing after five years through ten years, fair value	673
Available-for-sale securities, maturing after ten years, fair value	98
Available-for-sale securities, total, fair value	939
Held-to-maturity securities, maturing in one year, fair value	2
Held-to-maturity securities, maturing after one year through five years, fair value	69
Held-to-maturity securities, maturing after five years through ten years, fair value	22
Held-to-maturity securities, maturing after ten years, fair value	26
Held-to-maturity securities, total, fair value	119
Available-for-sale securities, maturing in one year or less, weighted average maturity in years	0.4
Available-for-sale securities, maturing after one year through five years, weighted average maturity in years	3.2
Available-for-sale securities, maturing after five years through ten years, weighted average maturity in years	7.8
Available-for-sale securities, maturing after ten years, weighted average maturity in years	10.7
Available-for-sale securities, total, weighted average maturity in years	7.3
Held-to-maturity securities, maturing in one year of less, weighted average maturity in years	0.6
Held-to-maturity securities, maturing after one year through five years, weighted average maturity in years	3.0
Held-to-maturity securities, maturing after five years through ten years, weighted average maturity in years	6.9
Held-to-maturity securities, maturing after ten years, weighted average maturity in years	23.3
Held-to-maturity securities, total, weighted average maturity in years	8.2
Available-for-sale securities, maturing in one year of less, weighted average yield	20.49%
Available-for-sale securities, maturing after one year through five years, weighted average yield	10.09%
Available-for-sale securities, maturing after five years through ten years, weighted average yield	4.12%
Available-for-sale securities, maturing after ten years, weighted average yield	2.56%
Available-for-sale securities, total, weighted average yield	5.00%
Held-to-maturity securities, maturing in one year of less, weighted average yield	1.06%
Held-to-maturity securities, maturing after one year through five years, weighted average yield	0.92%
Held-to-maturity securities, maturing after five years through ten years, weighted average yield	0.84%
Held-to-maturity securities, maturing after ten years, weighted average yield	0.74%
Held-to-maturity securities, total, weighted average yield	0.87%
Total investment securities amortized cost	1,012	1,197
Total investment securities, percentage	1.60%	2.30%
Other Debt Securities [Member]
Investment securities
Available-for-sale securities, maturing in one year or less, amortized cost	138
Available-for-sale securities, maturing after one year through five years, amortized cost	60
Available-for-sale securities, maturing after five years through ten years, amortized cost	31
Available-for-sale securities, maturing after ten years, amortized cost	1,207
Available-for-sale securities, total, amortized cost	1,436
Held-to-maturity securities, maturing in one year, amortized cost	1
Held-to-maturity securities, maturing after one year through five years, amortized cost	13
Held-to-maturity securities, maturing after five years through ten years, amortized cost	118
Held-to-maturity securities, maturing after ten years, amortized cost	0
Held-to-maturity securities, Obligations of foreign governments and other debt securities, amortized cost	132
Held-to-maturity securities, total, amortized cost	125	126
Available-for-sale securities, maturing in one year or less, fair value	136
Available-for-sale securities, maturing after one year through five years, fair value	57
Available-for-sale securities, maturing after five years through ten years, fair value	29
Available-for-sale securities, maturing after ten years, fair value	1,110
Available-for-sale securities, total, fair value	1,332
Held-to-maturity securities, maturing in one year, fair value	1
Held-to-maturity securities, maturing after one year through five years, fair value	11
Held-to-maturity securities, maturing after five years through ten years, fair value	95
Held-to-maturity securities, maturing after ten years, fair value	0
Held-to-maturity securities, Obligations of foreign governments and other debt securities, fair value	107
Available-for-sale securities, maturing in one year or less, weighted average maturity in years	0.6
Available-for-sale securities, maturing after one year through five years, weighted average maturity in years	1.1
Available-for-sale securities, maturing after five years through ten years, weighted average maturity in years	6.3
Available-for-sale securities, maturing after ten years, weighted average maturity in years	28.9
Available-for-sale securities, total, weighted average maturity in years	24.6
Held-to-maturity securities, maturing in one year of less, weighted average maturity in years	0.8
Held-to-maturity securities, maturing after one year through five years, weighted average maturity in years	2.2
Held-to-maturity securities, maturing after five years through ten years, weighted average maturity in years	7.2
Held-to-maturity securities, maturing after ten years, weighted average maturity in years	0
Held-to-maturity securities, total, weighted average maturity in years	6.7
Available-for-sale securities, maturing in one year of less, weighted average yield	6.27%
Available-for-sale securities, maturing after one year through five years, weighted average yield	6.66%
Available-for-sale securities, maturing after five years through ten years, weighted average yield	6.33%
Available-for-sale securities, maturing after ten years, weighted average yield	3.89%
Available-for-sale securities, total, weighted average yield	4.29%
Held-to-maturity securities, maturing in one year of less, weighted average yield	0.90%
Held-to-maturity securities, maturing after one year through five years, weighted average yield	1.30%
Held-to-maturity securities, maturing after five years through ten years, weighted average yield	0.91%
Held-to-maturity securities, maturing after ten years, weighted average yield	0.00%
Held-to-maturity securities, total, weighted average yield	0.95%
Other Investments [Member]
Investment securities
Available-for-sale securities, total, amortized cost	350
Held-to-maturity securities, total, amortized cost	0
Available-for-sale securities, total, fair value	402
Held-to-maturity securities, total, fair value	0
Available-for-sale securities, total, weighted average maturity in years	15.6
Held-to-maturity securities, total, weighted average maturity in years	0
Available-for-sale securities, total, weighted average yield	3.77%
Held-to-maturity securities, total, weighted average yield	0.00%
Other Debt Securities And Investments [Member]
Investment securities
Total investment securities amortized cost	$ 1,918	$ 1,887
Total investment securities, percentage	2.90%	3.50%